Polypropylene (PP), a chemically resistant commodity plastic, is occasionally functionalized with polar moieties in order to improve its compatibility with more polar polymers and fillers in composites. For example, in immiscible polymer blends (e.g., PP/Nylon blends), functionalized PP can be used to obtain reactive compatibilization as a result of in situ reaction between the polar moieties on the functionalized PP and the polar component of the blend (e.g., nylon). The most commonly produced (and studied) system of functionalized PP is maleic anhydride grafted PP (PP-g-MA). Currently, commercial production of PP-g-MA is achieved via melt processing, with PP being processed in the presence of low levels of initiator and maleic anhydride monomer. Melt processing, however, is accompanied by drastic molecular weight reduction of PP, which in turn results in dramatic loss in material properties of the product as compared to that of the neat PP from which it was made. The molecular weight reduction is caused by a free-radical chemistry (β-scission) that is highly dependent on temperature. (See FIG. 1.) As processing temperature increases, the rate of β-scission increases dramatically (See, Rätzsch, M.; Arnold, M.; Borsig, E.; Bucka, H.; Reichelt, N. Progress in Polymer Science 2002, 27, 1195-1282 and Dickens, B. Journal of Polymer Science: Polymer Chemistry Edition 1982, 20, 1169-1183). Because melt processing is carried out at high temperatures (e.g., ˜190-220° C.), the degree of β-scission and molecular weight reduction are typically quite significant. As a result, there remains an on-going concern in the art to develop an alternate, effective process for the preparation of functionalized polyolefins. This need has been recognized and documented clearly in the research literature: The incorporation of functional groups along the backbone of polyolefins such as polyethylene and polypropylene in a selective, controlled, and mild manner is one of the most important challenges currently facing synthetic polymer chemists. (See, Boaen, N. K.; Hillmyer, M. A. Chemical Society Reviews 2005, 34, 267-75.)